Their studies add to a growing body of evidence that at least some popular spices might slow or prevent the growth of cancer.

The study on ginger was done using cells in a lab dish, which is a long way from finding that it works in actual cancer patients, but it is the first step to testing the idea.

Dr. Rebecca Liu, an assistant professor of obstetrics and gynecology at the University of Michigan Comprehensive Cancer Center, and colleagues tested ginger powder dissolved in solution by putting it on ovarian cancer cell cultures.

It killed the ovarian cancer cells in two different ways -- through a self-destruction process called apoptosis and through autophagy in which cells digest themselves, the researchers told a meeting of the American Association for Cancer Research.

"Most ovarian cancer patients develop recurrent disease that eventually becomes resistant to standard chemotherapy, which is associated with resistance to apoptosis," Liu said in a statement.

"If ginger can cause autophagic cell death in addition to apoptosis, it may circumvent resistance to conventional chemotherapy."

Ovarian cancer kills 16,000 out of the 22,000 U.S. women who are diagnosed with it every year, according to the American Cancer Society.

Ginger has been shown to help control inflammation, which can contribute to the development of ovarian cancer cells.

"In multiple ovarian cancer cell lines, we found that ginger-induced cell death at a similar or better rate than the platinum-based chemotherapy drugs typically used to treat ovarian cancer," said Dr. Jennifer Rhode, who helped work on the study.

A second study found that capsaicin, which makes chili peppers hot, fed to mice caused apoptosis death in pancreatic cancer cells, said Sanjay Srivastava of the University of Pittsburgh School of Medicine.

"Capsaicin triggered the cancerous cells to die off and significantly reduced the size of the tumors," he said.

Last year the same team reported similar results with pancreatic cells in lab dishes. Pancreatic cancer is highly deadly, killing 31,000 of the 32,000 it will be diagnosed in this year.

Last month researchers in Los Angeles reported that capsaicin killed prostate tumor cells. Other studies have shown that turmeric, a yellow spice used widely in Indian cooking, may help stop the spread of lung cancer and breast cancer in mice.

Experts point out that many compounds shown to stop cancer in mice are not nearly as effective in human cancer patients.